Fig. 3

The kinetics of changes in PetCO₂ during incremental CPET in control, IPAH and CTEPH patients according to disease severity. PetCO₂ at rest, unloaded, AT, peak were significantly different among each subgroup of IPAH patients. In CTEPH patients, PetCO₂ were also markedly different among subgroups from unloaded to peak, but no obvious difference was found during rest. Each value is presented as mean ± SD. Statistical analysis was done by two-way ANOVA analysis. A: Contral versus mild, moderate, severe, very severe, respectively P < 0.05; Mild versus severe, very severe, respectively P < 0.05; Moderate versus severe, very severe, respectively P < 0.05; Severe versus very severe, P < 0.05. B: Contral versus mild, moderate, severe, very severe, respectively P < 0.05; Mild versus moderate, severe, very severe, respectively P < 0.05; Moderate versus severe, very severe, respectively P < 0.05